Rectal Sensory Threshold for Pain is a Diagnostic Marker of Irritable Bowel Syndrome and Functional Abdominal Pain in Children

Objective: To evaluate the diagnostic value of the rectal sensory threshold for pain (RSTP) in children and adolescents with chronic abdominal pain. Study design: Fifty-one patients (25 girls; median age 14.2 years; range 8.4-17.6) with abdominal pain >2 months underwent a series of rectal distensions with an electronic barostat. RSTP and viscerosomatic referrals were assessed. Three months after the barostat, the final diagnosis was documented. Results: Thirty-five patients had a functional gastrointestinal disorder (FGID) (irritable bowel syndrome or functional abdominal pain), and 16 had an organic disease. RSTP was lower in the FGID group than in the organic disease group (25.4mm Hg vs 37.1mm Hg; P = .0002). At the cutoff of 30mm Hg, the RSTP measurement for the diagnosis of FGID had a sensitivity of 94% and a specificity of 77%. Both groups similarly reported aberrant viscerosomatic projections. Conclusion: In children, RSTP is a diagnostic marker of irritable bowel syndrome and functional abdominal pain. Viscerosomatic referrals are similar in children with FGID and organic diseases.